Stay tape for boxes



Oct. 26, 1937. H. ATWATER STAY TAPE FOR BOXES Filed June 9, 1936 @www gev..

Patented Oct. 26, 1937 UNITED STATES PA'IENTy OFFICE 11 Claims.

The present invention relates to a stay tape, especially for the corners of fibre or cardboard boxes and is particularly directed to a tape which is suiliciently flexible to fit readily around the box corners.

In stay tapes used for reinforcing the corners of boxes the greatest strain on the tape is obviously laterally of the tape, as a result of the tendency of the box corner to tear open. One

of the features of the present invention resides in the provision of a reenforcement for the tape which will provide a substantially greater tensile strength laterally of the tape than longitudinally, without, at the same time, materially affecting the flexibility of the tape in either direction, so that the tape may be fitted readily to the box corner.

A stay tape of this character is frequently reenforced by a woven fabric combined with a layer of paper forming the tape, the fabric and paper being usually combined in relatively wide strips which are then cut longitudinally to form individual tapes of the desired Width. In using the low grade of fabric customarily considered to be satisfactory, the warp threads of the fabric, which extend longitudinally of the paper web as it is formed are not straight enough or sumciently widely spaced to permit cutting of the web between 'adjacent Warp threads without cutting into certain of these threads. A further feature of the invention resides in so arranging the warp threads that the relatively Wide web, as it is formed, may be cut up in'to narrow stay tapes of suitable widths without cutting across any of the warp threads.

Price is an important element in'the sale of these tapes and a large number of tapes of this character are built up using asphalt as the adhesive which holds the paper and the reenforcing fabric together, by reason of the low cost of this material. Although this type of adhesive is in general satisfactory in certain instances, it has a tendency, in hot weather, to run, and in cold weather to harden and crack. A further objec- 45 tion to asphalt is that the box cannot be reclaimed Without entirely removing all of the stay tape to which the asphalt is applied. A further feature of the present invention is the elimination of these objectionable features by the use of a different type of adhesive which incorporates all of the desirable characteristics of asphalt without its disadvantages.

Other and further objects and advantages oi the invention will appear from the following detailed description taken in connection with the accompanying drawing in whlch- Fig. 1 isa perspective view of a box to which the stay tape of the invention is applied.

Fig. 2 is a sectional view through a stay tape embodying the invention, the thickness of the material being .greatly exaggerated.

Fig. 3 is a plan view of a portion of a completed web from which the stay tape is cut.

Fig. 4 is a perspective view of the type of fabric used in the formation of the stay tape.

Fig. 5 is a sectional view through the corner of the box of Fig. l, showing the tape applied thereto, the thickness of the tape being greatly exaggerated.

Like reference characters refer to like parts in the different figures.

With reference rst to Fig. 1, the stay tape I of the invention is applied to the corner 01 a box 2 where the front and side walls 3 and 4 of the box come together. The tape forms a reenforcement which prevents the box from tearing at the corner and holds the adjacent sides of the box together. As will be apparent, the tape must reenforce the box especially in the direction of the reenforcing lines 5, which represent the reenforcing bres extending laterally of the stay tape, as this is the direction in which the box is most liable to tear. 'Ihe stay tape has adhesive applied to the under side thereof for easy attachment to the box and is relatively narrow since it is necessary only to have the tape extend far enough over the adjacent side walls of the box to assure a secure adhesive connection between the box and the tape.

Referring now to Figs. 2 and 3, the stay tape is made up of a strip of paper 6 of sufficiently heavy stock to present a smooth surface for contact with the box, and to the underside of the paper 6 is applied a suitable dry adhesive 1 of any usual character, by which the stay tape may be applied to the box.

On the upper side of the strip of paper 6 is positioned a woven fabric 8 by which the tape is reenforced in a lateral direction, the filler threads 9, as Vwill be apparent from Fig. 3, being more closely spaced than the warp threads I0. On the upper side of the fabric 8 is a covering strip of paper I l, which is preferably flexible and stretchable in all directions, as for example, the familiar crepe paper which is formed to provide stretch ln every direction, one form of this paper being shown in the Lorenz Patent No. 1,548,783, dated August 4, 1925, and another form being shown in the Kemp Patent No. 2,008,182, dated July 16,

1935. Either of these patents describes a process for producing a paper which is stretchable both longitudinally and laterally of the web. The strips of paper 8 and II are securely held together and to the fabric 8 by a flexible adhesive I2 of a type which is preferably soluble in water, as, for example, adhesive containing latex or sago, such as the commercially available "LotoY which is a colloidal suspension of latex in waterand other solvents. As be et shown in Fig. 2, the paper I I is pressed against the paper 8 so that the paper I I is embossed where the main threads of the fabric are located. Between adjacent threads of the fabric the paper 8 is pressed close enough to the paper II to adhere to the looseA fibers extending from the filler threads, these fibers being provided by a loose twisting of the filler threads. The two.sheets of paper are thus securely held together over substantially the entire surface, thereby avoiding any looseness in either paper sheet. This attachment is possible, by reason of the stretchability of the paper I I, without put'- ting enough strain on the paper II to tear it and without distorting the paper 6. The adhesive is used in as small quantities as possible and still have the tape stay together.

In the formation of the stay tape, the paper strips 6 and I I are positively secured to each other with the fabric 8 therebetween by passing the composite web, from which the tape is subsequently cut, between opposed rollers, one of which has a hard surface and engages the outer side of the sheet B. The other roll, which engages the outer side of the sheet II is relatively soft, preferably of rubber, so that the flexible paper II may be pressed inwardly toward the paper 6, thus forming indentations in the paper I I between the adjacent threads of the fabric 6. Since the paper II is stretchable in all directions it will be clear that portions of the paper can be offset from the normal plane of the paper to a substantial degree without affecting the stretchability thereof and without increasing the stiffness of the tape. The adhesive I2, as shown, is preferably applied to the fabric so that only a small quantity of adhesive is necessary to hold the sheets and fabric together.

As the tape is to be used on the corners of a box it must have its greatest strength in a lateral direction and the reenforcing fabric 8 is accordingly formed with the warp threads, which extend longitudinally of the tape, placed a substantial distance apart and the filler threads arranged relatively close together. One example of fabric of this character is shown in Fig. 4 which shows a Leno-weave fabric having the filler threads I3 very close together and the warp threads I4 arranged in pairs which are spaced a substantial distance apart, this distance in the preferred embodiment being 1/2 inch. Each pair of warp threads in the Leno-weave consists of two independent threads I4 which, between adjacent filler threads, cross each other not only in a plane perpendicular to the fabric, but also in the plane of the fabric, so that, as shown in this figure, the filler threads are tightly held by the warp in a uniformly spaced arrangement, and there is practically no lateral shifting of the warp threads on the filler threads. In order to produce an extremely inexpensive stay tape it is preferable to form the warp threads of relatively light cotton thread and to make the filler threads of jute, which is much less expensive than cotton. The filler threads can accordingly be arranged relatively close together to provide a stay tape which has a great amount of strength laterally without making the tape obiectionably expensive. 'Ihe strength of the tape is obviously controlled by the spacing of the illler threads. The flller threads preferably having a large number of loose fibre ends, a characteristic of jute threads, so that the filler threads are securely held against movement relative to the paper by the adhesive engaging with these fibres. The number and length of the loose libres is obviously controlled by the amount of twist given to the thread. ,f'

In the formation of stay tapes the fabric is preferably made up in webs of much greater width than the stay tape, and the sheets of paper 8 and II of similar width are applied to opposite sides of the full width web. After the sheets of paper 8 and II have been applied to the opposite sides of the fabric 8 the composite material is still much wider than the desired width for the stay tapes and the material is accordingly` cut longitudinally into the desired widths which are generally from 2 to 3 inches. With the spacing of the adjacent pairs of warp threads 1/2 inch from each other, it is clear that the stay tapes may be cut from the material along straight parallel lines I5 between adjacent warp threads without any possibility of any of the warp threads being cut during the formation of the tape. Obviously the warp threads form a longitudinal reenforcement for the tape so that the tape may in certain instances be used in sealing box coversas well as in reenforcing the corners.

Although it has been pointed out above that l the adhesive used in attaching the paper sheets to the fabric is preferably a water soluble adhesive, it will be apparent that other types of adhesive, such as thermo-plastic adhesives, may equally well be used and in fact in the production of an extremely inexpensive type of stay tape, Where the'use of asphalt is not objectionable, it is possible to use asphalt or other similar thermoplastic adhesives.

In the production of these stay tapes at a low cost it is desirable to crepe the paper I I just prior to the attachment of the several thicknesses of material together, and in the same machine. It is accordingly essential that the adhesive used be of a type which will permit the creping of the paper I I and the immediate application of the fabric 8 and paper Ii thereto without the necessity for drying the creped paper II and subsequently applying a special adhesive thereto. In the use of a thermoplastic adhesive the latter may also form the bond which secured the paper to the creping drum during the creping process and it will be apparent that water soluble adhesives may also be used for the same purpose with the paper immediately thereafter applied to the remainder of the materials making the stay tape without the necessity for Crying the crepe paper 5.

The creped or stretchable paper II is arranged to cover and protect the woven fabric, and thus prevent any threads of the fabric from being caught and pulled away from the box. The paper II also protects the adhesive so that the latter does not appear on the surface of the finished tape and can then be an undesirable color without affecting the salability of the tape. In order that the tape may be readily salable it can be produced in any desired color merely by making the paper I I the desired color before forming the tape. Since the paper II fully covers the tape, contrasting colors on the box and tape may be used to give the package an attractive appearance.

From the foregoing it will be apparent'that the present invention provides for a stay tape which is reenforced in a lateral direction by closely arranged bres located between ,paper sheets and thereby protected. The sheet of paper provided on its outside with adhesive for attachment to the box corner has a smooth outside surface for positive engagement with the box material over the entire surface of the tape. Moreover, since the paper sheet Il is stretchable the stay can be bent around the corner of the box without the formation of objectionable creases in the paper sheet 6, so that the paper sheet 6 will adhere to the box over the entire area of the stay'.v Further, the flexibility of the adhesive and of the paper Il permits the transverse reenforcing bres of the Woven fabric to move slightly relative to the paper 6 soA that the paper is allowed to bend around'the corner of the box without the formation of any objectionable creases in the paper 5. The creped paper i i obviously is thicker when creped than when uncreped, and the showing of Fig. 5 indicates an absence of creases at the bend in the stay tape by a relatively thinner paper at this point. It will be understood that the adhesive on the outside of the paper sheet S may be omitted and applied to the stay tape at the time that the tape is applied to the box.

I claim:

1. In a stay tape, a paper sheet,'a Woven fabric secured to one side of the paper sheet, and a stretchable paper sheet secured to the woven fabric on the side opposite to the first paper sheet, said stretchable paper sheet having indentations in which the threads of the fabric are positioned, the outside of the rst paper sheet being smooth.

2. In a stay tape, a paper sheet, a woven fabric secured to one side of the paper sheet, and a stretchable paper sheet secured to the Woven fabric on the side opposite to the rst paper sheet, said stretchable paper sheet having indentations in which the threads of the fabric are positioned, with said stretchable paper sheet engaging the loose fibres on the threads of the fabric between adjacent threads thereof.

3. In a stay tape, a paper sheet, a woven fabric secured to one side of the paper sheet, and a stretchable paper sheet secured to the woven fabric on the side opposite to the first paper, said stretchable paper sheet having indentations in which the bres of the fabric are positioned, said stretchable sheet having suiiicient stretch after the formation of the indentations to provide for exing the tape without creasing the first paper sheet.

4. In a stay tape, a paper sheet, and a fabric secured to one side thereof by a stretchable adhesive, said fabric having relatively close threads transversely of the tape and relatively widely spaced threads longitudinally thereof.

5. In a stay tape, a paper sheet, a woven fabricv having a Leno-weave secured to one side of said sheet, and a flexible adhesive securing said sheet and fabric together, the warp threads of the fabric extending longitudinally of the tape and being widely spaced, and the filler threads extending transversely of the tape and being 'closely extending transversely of the tape in close relation to each other. A

7. In a stay tape, a paper sheet, a woven fabric having a Leno-weave secured to one side of said sheet, a exible adhesive securing said sheet and fabric together, the warp threads of`the fabric extending longitudinally of the tape and being widely spaced, and the filler threads extending transversely of the tape and being closely spaced, and a stretchable paper sheet secured to the fabric and first paper sheet on the side of the fabric opposite to the first sheet.

8. In a stay tape, a paper sheet, a Woven fabric having a Leno-weave secured to one side of said sheet, a flexible adhesive securing said sheet and fabric together, the warp threads of the fabric extending longitudinally of the tape and being widely spaced, and the filler threads extending transversely of the tape and being closely spaced, a stretchable paper sheet secured to the fabric and rst paper sheet on the side of the fabric opposite to the first paper sheet, and adhesive on the side of the first paper sheet opposite to the fabric for securing the tape to a box.

9. In a stay tape, a paper sheet, a woven fabric securedto one side of the paper sheet, a stretchable paper sheet secured to the woven fabric on the side opposite to the rst paper sheet, said stretchable paper sheet having indentations in which the threads of the fabric are'positioned, the outside of the first paper sheet being smooth,

and a dry, water-soluble adhesive on the outside.

of said first sheet.

10. In a stay tape, a sheet of vmaterial to one side of which adhesive is applied in securing the tape to an article, a reenforcing material including spun fibers secured to one side of the first sheet and a stretchable paper sheet stretchable both longitudinally and laterally ofthe stay tape secured to the reenforcing material on the side opposite tothe rst sheet.

11. In a stay tape, a sheet of material to one side of which adhesive is applied in securing the tape to an article, a reenforcing material including spun fibers secured to one side of the rst sheet and a stretchable paper sheetstretchable both longitudinally and laterally of the stay tape secured to the reenforcing material on the side opposite to the first sheet, said stretchable paper sheet and the reenforcing material being secured to the rst sheet by an elastic adhesive.

i' HENRY ATWATER. 

